Durbin's letter came after a November hearing before the Senate Judiciary Committee in which Attorney General Eric Holder said the training in question was "flat-out wrong."

In his letter, Durbin said the FBI told him it had completed its review of the training program, but he said he was "disappointed" that the FBI doesn't seem to have any intention of providing a written report.

The FBI also told Durbin that it would not give his office copies of the presentations and documents that included offensive material.

"I am concerned that no one has been held accountable for providing this training ...," Durbin writes. "The FBI has not publicly apologized to the American-Muslim and Arab-American communities and it is my understanding that no one has been disciplined."

Concluding, Durbin asks the FBI to make unclassified material available to the public and that in the "very least, reassign the individuals responsible for providing inappropriate training."

The New York Times reports that last week, the Department of Justice released "guiding principles" for training materials. The Times reports:

"The documents said that such materials must be 'consistent with the Constitution' and agency values, including by not disparaging groups or individuals based on characteristics like race, religion, or national origin.

"The memorandums also say that supervisors must assess trainers for professionalism and to make sure that they are knowledgeable experts in the topic, and that they should review written materials being used for instruction."